getting IllegalArgumentsException and confused

[round hearth]

So im using HyperSkill and im on the last stage of the rock paper scissors game, here is a link to the stage and directions.
https://hyperskill.org/projects/314/stages/1768/implement
Anyway im confused on why i'm receiving an IllegalArgumentsException on my copyOfRange method in my determineWinner method. I know that it takes 3 arguments the Original Array the star and finish, as far as i can tell all my arguments are in range. Any help with helping me understand this and nudge me in the right direction would be greatly appreciated 🙂
here is my gist of what i have so far.
https://gist.github.com/AviTheBrown/848ee7b0ae63b788473c80818f3404e0

[frozen egret]

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[median creek]

This will give the error:
Exception in thread "main" java.lang.IllegalArgumentException: 0 > -1

import java.util.Arrays;

class Test {
    public static void main(String[] args) {
        String[] GameWeaponsArr = {"A", "B", "C"};
        int weaponIndex = Arrays.asList(GameWeaponsArr).indexOf("D");
        String[] firstArray = Arrays.copyOfRange(GameWeaponsArr, 0, weaponIndex);
        System.out.println(Arrays.toString(firstArray));
    }
}

What's the message of your IllegalArgumentException? It seems kind of important.

This will give the error:
Exception in thread "main" java.lang.IllegalArgumentException: 3 > 2

import java.util.Arrays;

class Test {
  public static void main(String[] args) {
    String[] GameWeaponsArr = {"A", "B", "C"};
    int weaponIndex = Arrays.asList(GameWeaponsArr).indexOf("C");
    String[] secondArray = Arrays.copyOfRange(GameWeaponsArr, weaponIndex + 1, GameWeaponsArr.length -1);
    System.out.println(Arrays.toString(secondArray));
  }
}

Consider printing out your indexes..

@round hearth ^

[round hearth]

@median creek yeah i changed it to this

   private String setWeapons(String gameWeapons) {
        if (gameWeapons.equals("")) {
            gameWeapons = "rock,paper,scissors";
        }
        GameWeaponsArr = gameWeapons.split(",");
        // encase the user accidentally presses the space bar.
        return gameWeapons.replace(" ", "");
    }

[median creek]

In any case, you should give us the entire error message, and not just the type :)

[round hearth]

and

 private void determineWinner(String userWeapon, String computerWeapon) {
        // the first array is the elements that are listed before the selectedWeapon
        String[] firstArray = Arrays.copyOfRange(GameWeaponsArr, 0, weaponIndex);
        // the second Array are all the elements that are listed after the selectedWeapon
        String[] secondArray = Arrays.copyOfRange(GameWeaponsArr, weaponIndex + 1, GameWeaponsArr.length);


        List<String> newWeaponList = new ArrayList<>(Arrays.asList(secondArray));
        newWeaponList.addAll(Arrays.asList(firstArray));
        // creates a new Array, which is a concatenation of first array and second Array
        String[] finalArray = newWeaponList.toArray(new String[0]);
        List<String> firstHalfOfList = new ArrayList<>(newWeaponList.subList(0, newWeaponList.size() /2));
        List<String> seconsHalfOfList = new ArrayList<>(newWeaponList.subList((newWeaponList.size() / 2) + 1, newWeaponList.size()));
        List<String> gameWeaponList = new ArrayList<>(Arrays.asList(GameWeaponsArr));
        ...
    }

[round hearth]

ok 🙂

one sec

[median creek]

The error message will give you the indexes, no?

[round hearth]

see i fixed it. but ..

[median creek]

..and the error will also say which of the two calls to copyOfRange that is the problem by mentioning the line number.

But?.. I don't have a magnifying glass :)

[round hearth]

for some reason it doesn't handle the invalid input nor does it account for the rules set by the project

lol i was typing

let me upload an undated gist

updated*

https://gist.github.com/AviTheBrown/848ee7b0ae63b788473c80818f3404e0

[median creek]

I don't think I'll be able to fix your project. I just wanted to help you with the error you mentioned.

What I mean to say is that I didn't plan to read 120 lines of code and figure out the error in the design.

[round hearth]

ok. so i fixed the empty null array. but it still presents itself when invalid input is submitted.

[median creek]

May I ask why you're putting in an image instead of copy pasting the error?

So what happens when it can't find the choice in the list?.. Look at my first example.

Are you handling this situation?

It seems you are not:

  int weaponIndex = Arrays.asList(GameWeaponsArr).indexOf(userWeapon);
  // the first array is the elements that are listed before the selectedWeapon
  String[] firstArray = Arrays.copyOfRange(GameWeaponsArr, 0, weaponIndex);

You're using the weaponIndex without checking if it's -1 first.

How do you set the userInput?

[round hearth]

i would put the code but sometimes its too large. and i just wanted to show you the exception that was produced.
thats actually really smart. i didnt think to check if it throws and exeception. i will try that.

[median creek]

I see that seems to be fine.. but I'm pretty sure your error comes from the fact that you don't handle the situation when a user doesn't pick any of the tree options.